Infrared spectroscopy of gas hydrate dissociation behavior during depressurization

Abstract

The dissociation of gas hydrates by depressurization was investigated by attenuated total reflection infrared (ATR-IR) spectroscopy. A discrete change in temperature and the first moments of the O-H group absorption band of H 2O molecules were observed during hydrate dissociation in porous media. These discrete changes indicate ice formation in the pores. Assuming that the first moments were determined by the ratio of the liquid to solid H 2O molecules on the contact area of the ATR window, we estimated the formation rate of ice from the variation in the first moment during hydrate dissociation. © 2009 The Japan Society of Applied Physics.